Dec, 1921 Bulletin of the Brooklyn Entomological Society 135 



tocorisa, etc., where the pake are shorter and broader, and flat or 

 even concave on the side which is apphed to the face in feeding. 

 In fact, the structure of the palae in Cymatia is such as to suggest 

 carnivorous habits, the palar bristles as well as the long movable 

 terminal claw indicating their use in the retention of prey. 



That these structures are employed in this manner has been 

 observed directly. For about ten weeks during the winter of 

 1920-21 I kept a pair of Cymatias in a small balanced aquarium 

 on my table. On November 24 several larvae of a Corethra were 

 placed in this aquarium also, and a few days later one of the 

 Corixids was seen to be feeding on a Corethra, holding it tightly 

 pressed to its face by means of its front legs ; but the Corethra 

 was released before I could make any close observations. 



On December 19 the stock of Corethras had become exhausted, 

 and more were added to the aquarium. Almost at once one of 

 the Cymatias, which was at rest on the bottom, struck at one of 

 the larvae, but missed; it then floated up toward the surface, 

 directly under another of the larvae. When about one centimeter 

 below the Corethra, the bug gave a quick stroke upward, turned 

 on its side, seized the larva, and swam down to the bottom, where 

 it proceeded to feed on its prey. The Cymatia held the Corethra 

 closely pressed against its face by means of its front legs, the 

 palar bristles of which crossed each other forming a sort of net 

 which helped to hold the prey, while the palar claws were bent 

 nearly at a right angle with the pala and closely pressed against 

 the larva. The mandibular and maxillary stylets of the Cymatia 

 were protruded considerably from the oral aperture, and were 

 worked rapidly back and forth in the body of the larva. After 

 twenty minutes the Corethra ceased to move; though at first its 

 struggles were so strong as to dislodge the Corixid's hold on the 

 bottom, they were not sufficient for it to escape. During the 

 feeding process the Corixid manipulated the Corethra somewhat, 

 sometimes holding it straight and at other times in the form of 

 a U. After sixty minutes the bug came to the surface for the 

 first time after it began feeding, and ten minutes later the 

 Corethra was dropped, now shrunken to about two-thirds of its 

 normal length. 



